The True Cost of a Blower: Why Energy Dwarfs the Purchase Price

By the NextAir Systems engineering team. Last reviewed October 2026.

Blowers are bought on price and paid for in electricity. A large industrial fan running most of the year uses more energy in a few months than it cost to buy, and the gap widens every year after that. This is well known and routinely ignored, because the purchase order and the electricity bill belong to different budgets.

The arithmetic is short. We build a 15-year cost model for a 110 kW blower, with the assumptions stated so you can substitute your own, and show what a few points of efficiency are worth.

The short version

• A blower drawing 110 kW at the shaft for 8,000 hours a year uses about 921,466 kWh of electricity. At USD 0.08 per kWh over 15 years at an 8% discount rate, the present value of that energy is about USD 630,981.
• Against an assumed purchase and installation cost of USD 85,000, energy is 86% of the total cost of ownership.
• Three points more efficiency (78% to 81%) saves about 34,128 kWh a year, or roughly USD 2,730 a year at USD 0.08 per kWh.
• DOE guidance on fan systems warns that decisions based on lowest initial cost instead of life-cycle cost can be unwise.^[1]

The model

The cost of owning a blower has four parts: the purchase and installation, the electricity, the maintenance, and the cost of downtime. We model the first three. Downtime is real and very process-specific, so we leave it out, which makes the energy share we calculate conservative.

• Shaft power 110 kW, motor efficiency 95.5%, running 8,000 hours a year.
• Purchase and installation USD 85,000, maintenance 3% of that each year.
• A 15-year life and an 8% discount rate, which gives a present-value factor of 8.56 on a level annual cost.

The annual electricity is 110 ÷ 0.955 × 8,000 = 921,466 kWh. Multiply by the electricity price and the present-value factor and you get the present value of the energy over the life.

Across a wide range of prices, electricity is between about 79% and 90% of the total. The prices are illustrative, so use your own tariff. The conclusion does not change: the purchase price is a minority of what you spend. This is consistent with the general finding that energy is the largest share of the life-cycle cost of motor-driven equipment, which Sulzer’s technical article on motor efficiency makes for pumps, and which applies equally to fans.^[2]

What efficiency is worth

Worked example. Suppose one blower offers 78% total efficiency and another 81% at the same duty. For the same airflow and pressure, shaft power scales inversely with efficiency, so the better blower needs 105.9 kW instead of 110 kW. That is 4.1 kW less, or 34,128 kWh a year including the motor. At USD 0.08 per kWh it is USD 2,730 a year, and over 15 years at 8% its present value is about USD 23,370. The 81% blower could cost that much more and still break even.

The break-even premium is the number to use when comparing quotations. It lets you say how much extra a higher efficiency is worth paying, and it is usually large compared with the price differences you actually see, as we describe in comparing quotations like for like.

Where the energy goes, and where it can be saved

• Selection. A fan chosen to run near its best efficiency point uses less energy than one running far from it. The system and fan curves in the operating point guide show how to check.
• Control. A damper wastes energy as pressure drop. Speed control saves it, as covered in flow control for blowers.
• Motor. Each IEC efficiency class step reduces motor losses by roughly 20%. See motor efficiency for blower drives.
• System. Ducts, bends and entry conditions add pressure drop that the blower must overcome, so they set the shaft power as surely as the blower does. For burner fans the airflow itself comes from the fuel, as in combustion air sizing.
• Margin. Oversizing the blower and throttling it is one of the most expensive habits in industry.

Sensitivity: which assumption matters most

Run the same model with a different discount rate or life and the energy share barely moves. Halve the running hours to 4,000 and the energy present value halves to about USD 315,491, which still leaves it more than three times the purchase price. The two inputs that change the picture are the hours and the tariff. A standby fan that runs 500 hours a year is a capital decision, and a process fan that never stops is an energy decision, and the specification should reflect which one you are buying.

What the model does not capture

Real life is messier. Electricity prices change, and for a 15-year life the safest assumption is that they rise. Duty varies, so the hours at full load are fewer than the running hours. Maintenance depends on the design, and downtime costs can exceed everything above. But none of these arguments favours buying on price alone, and several of them strengthen the case for efficiency and reliability. The best response is to do the calculation with your own numbers and put the answer in front of whoever approves the purchase.

Where this fits with NextAir

NextAir manufactures centrifugal blowers up to 800 HP and 500 mm WC, in MS, SS and high-temperature construction, and we will give a shaft power and efficiency at your duty point that you can use in this calculation. Send your airflow, pressure, gas condition and hours to our centrifugal blower manufacturer team. Our guide to centrifugal blowers covers the range, and cement plants and power generation are typical high-hours duties.

Sources

1. Plant Engineering (US DOE Motor System BestPractices material). Building energy efficiency into fan systems.
2. Sulzer. A lifetime of efficiency (technical article on IE3 motors).

Figures and tables on this page are calculated or compiled by NextAir Systems and you are welcome to reuse them with a link back to this article.

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